Field of the Invention
The invention relates to a hearing assistance system, comprising a first hearing device to be worn at a first one of a user's ears, and a second hearing device to be worn at a second one of the user's ears, with each hearing device being adapted to establish a binaural data link between the first hearing device and the second hearing device and comprising a BLUETOOTH® (“BT”) interface for wireless reception of an external audio data stream from an external device, such as a phone device.
Description of Related Art
When transporting audio, BLUETOOTH® Classic profiles, such as the Advanced Audio Distribution Profile (A2DP) or the Hands Free Profile (HFP), offer a point-to-point link from an audio source to an audio destination.
Typically, the interface for binaural communication, which may use an inductive link, is a short range interface having lower power consumption than the BLUETOOTH® interface.
Since power consumption is an issue for ear level devices, binaural hearing assistance systems have been developed, wherein the external audio stream is received only by one of the hearing devices via the long range interface and is forwarded to the other device via the binaural short range interface.
U.S. Pat. No. 8,300,864 B2 relates to a binaural hearing aid system, wherein an audio stream from a telephone device is transmitted via a short range inductive link to one of the hearing aids and is forwarded via a second wireless link which is used by the hearing aids to exchange data to the other hearing aid.
U.S. Pat. No. 8,041,066 B2 relates to a binaural hearing aid system, wherein one of the two stereo channels received by one of the hearing aids via a wireless link is forwarded to the other hearing aid via a wireless link.
Other examples wherein an audio stream received via a BT link from an audio source is relayed to the other ear are described in U.S. Pat. Nos. 8,706,038 B2, 9,002,044 B2 and 8,155,335 B2, wherein the binaural link likewise may be a BT link (U.S. Pat. Nos. 8,706,038 B2 and 9,002,044 B2) or may be an NCF link (U.S. Pat. No. 8,155,335 B2)
U.S. Patent Application Publication 2009/0197532 A1 relates to a pair of earphones, wherein in a first mode one of the earphone receives an audio stream via a BT link from a mobile phone and relays it via a different wireless link to the other earphone, and wherein in a second mode the roles of the earphones are interchanged; switching between the two modes occurs according to the battery levels of the earphones in order to achieve balanced battery drain.
U.S. Patent Application Publication US 2011/0158441 A1 relates to similar system comprising a pair of BT earphones, wherein the wireless link connecting the earphones is a BT link like the BT link via which the audio stream from the mobile phone is received; the roles of the earphones are switched according to the respective battery levels.
U.S. Pat. No. 8,526,648 B2 relates to a binaural hearing assistance system, wherein an audio signal from a wireless microphone is transmitted to the hearing devices, wherein the link quality to each hearing device is monitored, and wherein the signal received via the better link is relayed via a binaural link to the other hearing device.
International Patent Application Publication WO 2010/008861 A2 relates to a network system, wherein information concerning the BT protocols/services available for a device of the system is communicated to other devices in the network via another network link, such as WiFi.
U.S. Patent Application Publication US 2010/0167652 A1 relates to a system comprising a mobile phone and a BT headset, where there is an internal protocol switching in the mobile phone depending on the use situation.
According to U.S. Pat. No. 8,150,323 B2, the BT connection from a mobile phone to a headset may be changed according to the presence of a phone call from a simplex to a duplex mode when music is played.
U.S. Pat. No. 8,050,439 B2 relates to a binaural hearing system, wherein a bidirectional wireless link between the two hearing aids as used to exchange information concerning the battery charge status of each hearing aid in order to reduce power consumption of the hearing aid having the lower remaining battery lifetime once the difference of the remaining battery charges exceeds a certain limit.
U.S. Pat. No. 8,712,083 B2 relates to data logging in a wireless hearing aid system in order to modify link parameters in a manner to enhance reliability and link quality.